Propagation and quantification of obligate intracellular pathogens are both labor-intensive and costly undertakings. These characteristics, coupled with C. burnetii's highly infectious nature and select agent designation, complicate the most basic research endeavors. However, because highly purified and enumerated C. burnetii is essential to the proposed research, a dedicated core facility with BSL 3 containment, highly trained technical personnel, and an archival system is proposed. Thus, the purpose of the Core B is to make available to each of the 4 Montana Coxiella projects expertise in the cultivation, purification, enumeration, and archiving of phase 1 and 2 Coxiella burnetii. The core will be located at Montana State University, the location of the BSL-3 facilities, and will be directed by Allen Harmsen of Montana State University. Collaborations among projects. Core B will provide services to each of the 4 research projects of the Montana Coxiella group as well as any other RMRCE investigator needing their service. These services will include making standardized inocula of phase 1 and 2 Coxiella burnetii as well as the Crazy strain of Coxiella, as well as the services of standardized Coxiella enumeration and archival of Coxiella organisms. In addition, the two part- time technicians are trained specifically in doing lung infections in mice in the BSL-3. When not engaged in their other activities, the Core B technicians will be available to assist the 4 Montana Coxiella projects on days they sacrifice mice since these time points are labor intensive. Our BSL3 SOP requires a "buddy system" and individuals are not allowed to work alone in the facility. It is much more economical to have two part time floating positions rather than for each of the individual research projects to fund full time technicians to cover these occasional, labor-intensive time points. Therefore, the core is integral and critical to the goals of each of the projects and required for consistency between projects so that results between projects can be directly compared. Core B will support the RMRCE Integrated Research Foci on Immunomodulation, Adjuvants and Vaccines (IRF 1) as well as Bacterial Therapeutics (IRF 2), and its resources will be utilized by RPs 1.1, 1.2, 1.3, and 2.4.